This part of Chapter 2 of the Gospel of Mark is focused on the idea of the law and of the relationship between Jesus and that law. A tension is set up in this section of the chapter between what the law says and what Jesus and his people can do. By setting up this tension, the author is highlighting the differences between Christianity and Judaism.
Jesus and his followers are questioned in this part of the chapter about their breaking of Jewish law regarding fasting and the sabbath. Jesus replies by saying essentially that the Jewish law does not apply to him. He claims that he is special, the "Son of Man," and that his authority is higher than that of the law. He also seems to be saying that he has brought a new law. That is why he talks about the new wine and the new cloth and their incompatibility with old wineskins and old cloth.